1. Field of the Invention
The present invention relates to an image processing apparatus and a recording medium recording an image processing program that process a color static image or color dynamic image to provide a desired tone.
2. Description of the Related Art
Image pickup apparatuses, such as digital cameras, have been remarkably developed in recent years. However, they have not yet achieved as high dynamic range as that of human vision. For example, when a flash is used to shoot a static image, closer ranges are brightly illuminated and further ranges are poorly illuminated. And it is difficult to reproduce the same tone as that perceived by human vision both in the closer ranges and the farther ranges in the static image.
Space-variant tone conversion recently proposed is a solution to the problem. For example, in Japanese Patent Application Laid-Open Publication No. 2001-118062, there is a technique described of analyzing the texture of an input image, dividing the input image into a plurality of regions based on the result of the analysis, and performing a different density conversion processing on each of the divisional regions. According to the technique, even when a scene includes parts considerably different in brightness, the tones can be faithfully reproduced both in the bright parts and the dark parts, and an image of a subject close to that perceived by human vision can be produced.